BASIC CLINICAL SUMMARY AND STEPWISE APPROACH TO HYDROCEPHALUS
- 1. HYDROCEPHALUS Dr. Rafia.Iqbal. M.B.B.S. M.D. D.C.H Department of Pediatrics IMTU
- 2. OUTLINE • DEFINITION • AETIOLOGY • PATHOPHYSIOLOGY • CLINICAL FEATURES • MANAGEMENT Investigations Treatment • COMPLICATIONS • PROGNOSIS
- 3. DEFINITION • DIVERSE GROUP OF CONDITIONS CHARACTERISED BY EXCESSIVE CSF IN THE BRAIN. THUS: 1. IMPAIRED FLOW 2. DECREASED REABSORPTION 3. INCREASED PRODUCTION
- 4. HYDROCEPHALUS DEFINITION: DIVERSE GROUP OF CONDITIONS WHICH RESULT FROM IMPAIRED CIRCULATION AND RESORPTION OF CSF. OR • RARELY from increased production by a choroid plexus papilloma.
- 5. CSF FORMATION • CSF IS FORMED BY THE CHOROID PLEXUS. in the lateral, third, and fourth ventricles. • NORMAL CSF PRODUCTION: 20 ml/h. • Total volume of CSF approximates 50?mL in an infant and 150?mL in an adult
- 6. FLOW OF CSF
- 7. TYPES OF HYDROCEPHALUS • OBSTRUCTIVE OR NON-COMMUNICATING (OBSTRUCTION WITHIN THE VENTRICULAR SYSTEM) • NON OBSTRUCTIVE OR COMMUNICATING (MALFUNCTION OF ARACHNOID VILLI)
- 8. CAUSES OF HYDROCEPHALUS • LESIONS OR MALFORMATIONS OF THE POSTERIOR FOSSA – CHIARI MALFORMATION – DANDY- WALKER SYNDROME – TUMORS • IVH • MENINGITIS: PNEUMOCOCCAL, TB • INTRAUTERINE INFECTIONS
- 9. PATHOLOGY • AQUEDUCTAL STENOSIS: – ABNORMALLY NARROW AQUEDUCTUS OF SYLVIUS. • AQUEDUCTAL GLIOSIS: – BRISK GLIAL RESPONSE OF EPENDIMAL LINING
- 10. CHIARI MALFORMATION TYPE I: – DISPLACEMENT OF CEREBELLAR TONSILS INTO THE CERVICAL CANAL. – the pathogenesis is unknown, • ?? obstruction of the caudal portion of the fourth ventricle during fetal development. -GIVES SYMPTOMS IN ADOLESCENCE OR ADULT LIFE. (HEADACHE, NECK PAIN) – NO HYDROCEPHALUS.
- 12. CHIARI MALFORMATION • TYPE II : – PROGRESSIVE HYDROCEPHALUS AND MYELOMENINGOCELE. ELONGATION OF THE 4TH VENTRICLE. – DISPLACEMENT OF INFERIOR VERMIS, PONS, AND MEDULLA INTO CERVICAL CANAL This lesion represents an anomaly of the hindbrain
- 13. • produce symptoms during infancy • stridor, weak cry, and apnea, diff in feeding, choking, pooling of secretions, paralysis of vocal cords
- 14. DANDY-WALKER SYNDROME • CYSTIC EXPANSION OF THE 4TH VENTRICLE IN THE POSTERIOR FOSSA. • DEVELOPMENTAL FAILURE OF ROOF OF 4TH VENTRICLE DURING EMBRYOGENESIS. • 90 % HAVE HYDROCEPHALUS • PROMINENT OCCIPUT
- 15. IVH • DEFINITION: – BLEEDING IN SUBEPENDIMAL GERMINAL MATRIX WITH/WITHOUT EXTENSION INTO VENTRICLES AND BRAIN PARENCHYMA • INCIDENCE: – IN PREMATURES 25 - 40 %
- 16. IVH • PATHOLOGY: – INTRAVASCULAR – VASCULAR – EXTRAVASCULAR • COMPLICATIONS: – HYDROCEPHALUS • 20 % IN MODERATE BLEEDS • 65-100 % IN LARGE BLEEDS.
- 17. PREVENTION OF IVH • AVOID PROLONGUED LABOR OR DIFFICULT VAGINAL DELIVERY • AVOID PNEUMOTHORAX • AVOID OF HYPOTENSION OR HYPERTENSION IN THE NEONATE • AVOID HYPOXIC ISCHEMIC INSULT
- 18. PREVENTION OF IVH • INDOMETHACIN • PROPHYLACTIC FFP?? • PROPHYLACTIC PLATELET TRANSFUSION??? • PHENOBARBITAL??? • VITAMIN E ???
- 19. Non obstructive or communicating 1. Sub arachnoid haem after IVH in a premature inf 2. Pneumococcal and tuberculous meningitis produce a thick, tenacious exudate that obstructs the basal cisterns 3. Intrauterine infections may also destroy the CSF pathways. 4. Finally, leukemic infiltrates may seed the subarachnoid space and produce communicating hydrocephalus.
- 20. CLINICAL MANIFESTATIONS • SYMPTOMS: – IRRITABILITY – POOR FEED – LETHARGY – VOMITING – IN OLDER PATIENTS: • HEADACHE • CHANGES IN PERSONALITY • ACADEMIC DETERIORATION
- 21. CLINICAL MANIFESTATIONS • SIGNS: – ANTERIOR FONTANEL WIDE OPEN AND BULGING, INCREASED HEAD CIRC. – DILATED SCALP VEINS – SETTING SUN SIGN – BRISK TENDON REFLEXES, SPASTICITY – CLONUS, BABINSKY SIGN +VE – MACEWEN SIGN “CRACKED POT” – PROMINENT OCCIPUT (DANDY-WALKER)
- 22. • A gradual change in personality and deterioration in academic productivity suggest a slowly progressive form of hydrocephalus. • Serial measurements of the head circumference indicate an increased velocity of growth. >2 cm in 2 weeks • The size and configuration of the anterior fontanel are noted
- 23. • Percussion of the skull may produce a “cracked- pot” or Macewen Sign, indicating separation of the sutures. • A foreshortened occiput suggests Chiari malformation • Prominent occiput suggests the Dandy-Walker malform • Papilledema, abducens nerve palsy.
- 24. • A cranial bruit: - audible in vein of Galen arteriovenous malformation. • Transillumination:- of the skull is positive with massive dilatation of the ventricular system or in the Dandy-Walker syndrome. • Funduscopy: is mandatory, chorioretinitis suggests an intrauterine infection such as toxoplasmosis
- 25. • The size and configuration of the anterior fontanel are noted • Back is inspected for abnormal midline skin lesions, including tufts of hair, lipoma, or angioma that might suggest spinal dysraphism.
- 26. • Papilledema is observed in older children • Plain skull films typically show separation of the sutures, erosion of the posterior clinoids in an older child, and an increase in convolutional markings (beaten-silver appearance) with long- standing increased ICP.
- 27. • Chiari malformation consists of two major subgroups; TYPE I • symptoms during adolescence or adult life and is usually not associated with hydrocephalus. • C/O recurrent headache, neck pain, urinary frequency, and progressive lower extremity spasticity.
- 28. • The deformity consists of displacement of the cerebellar tonsils into the cervical canal. • Although the pathogenesis is unknown, ?? obstruction of the caudal portion of the fourth ventricle during fetal development is responsible.
- 30. IMAGING STUDIES • X-RAY PLAIN FILMS: – SEPARATION OF SUTURES – EROSION OF POSTERIOR CLINOIDS – INCREASED CONVOLUTIONAL MARKINGS (BEATEN SILVER APPEAREANCE) • ULTRASOUND • CT SCAN • MRI
- 31. D/D • The head may appear enlarged and be confused with hydrocephalus secondary to a • thickened cranium resulting from chronic anemia, rickets, osteogenesis imperfecta, and epiphyseal dysplasia. • Chronic subdural collections can produce bilateral parietal bone prominence. • Metabolic and degenerative disorders of the CNS produce megalencephaly due to abnormal storage of substances within the brain parenchyma.-mucopolyaccharidoses
- 32. • cerebral gigantism and neurofibromatosis are characterized by increased brain mass. • Familial megalencephaly is inherited as an autosomal dominant trait and is characterized by • delayed motor milestones and hypotonia but normal or near-normal intelligence. • Measurement of the parent's head circumference is necessary to establish the diagnosis.
- 33. • Hydranencephaly may be confused with hydrocephalus. The cerebral hemispheres are absent or represented by membranous sacs with remnants of frontal, temporal,or occipital cortex dispersed over the membrane. The midbrain and brainstem are relatively intact • The cause of hydranencephaly is unknown,
- 34. • normal or enlarged head circumference at birth that grows at an excessive rate postnatally. Transillumination shows an absence of the cerebral hemispheres. • child is irritable, feeds poorly, develops seizures and spastic quadriparesis, and has little or no cognitive development. • A ventriculoperitoneal shunt prevents massive enlargement of the head
- 35. THERAPY • MEDICAL: – ACETAZOLAMIDE – FUROSEMIDE • SURGICAL: – V-P SHUNT PLACEMENT --VENTRICULOSTOMY MAY SUFFICE FOR SOME
- 36. The major complication of shunts 1. bacterial infection, Staphylococcus epidermidis 2. blocks
- 37. PROGNOSIS • INCREASED RISK FOR DEVELOPMENTAL DISABILITIES • MEAN IQ IS REDUCED COMPARED TO GENERAL POPULATION • ABNORMALITIES IN MEMORY • SOME PATIENTS SHOW AGGRESSIVE OR DELINQUENT BEHAVIOR.
- 38. PROGNOSIS • VISUAL PROBLEMS: – STRABISMUS – VISUOSPATIAL ABNORMALITIES – DECREASED VISUAL ACUITY – VISUAL FIELD DEFECTS • PATIENTS REQUIRE LONG TERM FOLLOW UP (MULTIDISCIPLINARY)
- 39. Microcephaly Microcephaly is defined as a head circumference that measures > two- ?three standard deviations below the mean for age and sex. This condition is relatively common, particularly among the mentally retarded population.
- 40. • There are many causes of microcephaly • Abnormalities in neuronal migration during fetal development are found in many brains
- 41. • Microcephaly may be subdivided into two main groups: 1) primary (genetic) 2) secondary (nongenetic) • A precise diagnosis is important for genetic counseling and for prediction for future pregnancies.
- 42. Etiology • Primary microcephaly : a group of conditions that usually have no other malformations and follow a mendelian pattern of inheritance OR • are associated with a specific genetic syndrome.
- 43. Etiology • Affected infants are usually identified at birth because of a small head circumference. • The more common types include familial and autosomal dominant microcephaly • Associated with a series of chromosomal syndromes
- 45. • Secondary microcephaly: large number of noxious agents that may affect a fetus in utero or an infant during periods of rapid brain growth, particularly the first 2 yr of life.
- 47. Clinical Manifestations and Diagnosis • A thorough family history should be taken, seeking additional cases of microcephaly or disorders affecting the nervous system. • It is important to measure the child’s head circumference at birth. • A very small head circumference implies a process that began early in embryonic or fetal development. • An insult to the brain that occurs later in life, particularly beyond the age of 2 yr, is less likely to produce severe microcephaly.
- 48. Clinical Manifestations and Diagnosis • Serial head circumference measurements are more meaningful than a single determination, particularly when the abnormality is minimal. • In addition, the head circumference of each parent and sibling should be recorded.
- 49. • Laboratory investigation of a microcephalic child depends the history and physical examination. • If the cause of the microcephaly is unknown, the mother's serum phenylalanine level should be determined. • High phenylalanine serum levels in an asymptomatic mother (behaves like a teratogen) can produce marked brain damage in an otherwise normal non-phenylketonuric infant.
- 50. • A karyotype :- chromosomal syndrome is suspected or if the child has abnormal facies, short stature, and additional congenital anomalies. • CT scanning or MRI :- identify structural abnormalities of the brain or intracerebral calcification.
- 51. • Additional studies 1)a fasting plasma and urine amino acid analysis; 2)serum ammonium determination 3) toxoplasmosis, rubella, cytomegalovirus, and herpes simplex (TORCH) titers of the mother and child; 4) urine sample for the culture of cytomegalovirus.
- 52. Management • Once the cause of microcephaly has been established, • the ped must provide accurate and supportive genetic and family counseling. • Because many children with microcephaly are also mentally retarded, he must assist with placement in an appropriate program that will provide for maximum development of the child